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A quantification model for apoptosis in mouse embryos in the early stage of fetation

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Science China(Life Sciences) 2009年第10期52卷 922-927页

作者： WANG PengFei1, FU JianHua1, MA WanYun1, CHEN DieYan1, Lü DanYu2.& BAI WenJia3 1 Key Laboratory for Atomic and Molecular Nanosciences of Education Ministry, department of physics, Tsinghua university,{2. 100084, China 2.department of Anatomy & Histology and Embryology, School of Basic Medical Sciences peking university Health Science Center,{2. 100083, China 3 department of Automation, Tsinghua university,{2. 100084, China 1. Key Laboratory for Atomic and Molecular Nanosciences of Education Ministry Department of Physics Tsinghua University Beijing 100084 China 2. department of Anatomy & Histology and Embryology School of Basic Medical Sciences Peking University Health Science Center Beijing 100083 China 3. department of Automation Tsinghua University Beijing 100084 China

Apoptosis is the most important inducement and modulator for embryos in the early stage of fetation, i.e. after the 8-cell stage, mostly the morula and blastula stage, to proceed to the stage of nonlinear development. Using a two-photon laser scanning microscopy (TPLSM) system, we obtained 3-dimensional (3D) fluorescent images of preimplantation mouse embryos. A model for quantification was established. The statistical results for the spatial location of apoptosis bodies in embryos was obtained following image processing, as well as investigation of the kinetics of apoptosis. It was found that most (70%) apoptosis occurred in the trophectoderm, and the departure between the centroid and geometric center of embryos had a step transition when embryos developed into the 32.cell stage, which was consistent with the theoretical prediction that the blastocele would induce a symmetry break of the distribution of cells in embryos.

关键词： apoptosis preimplantation mouse embryo TPLSM quantification model

Existence of entire explosive positive radial solutions of sublinear elliptic systems

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Communications in Nonlinear Science and Numerical Simulation 2001年第2期6卷 88-92页

作者： Zuodong YANG and Qishao LU department of Applied Mathematics, peking university of Aeronautics and Astronautics,{2. 100083, China department of Applied Mathematics Peking University of Aeronautics and Astronautics Beijing 100083 China

In this paper, our main purpose is to establish the existence of entire explosive positive radial solutions of quasilinear elliptic systems. The main results of the present paper are new and extend the previously know... 详细信息

关键词： quasilinear elliptic system entire explosive positive solution existence

Anisotropic Scattering in BaTiO3: Ce Single Crystal

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Chinese Journal of Lasers 1997年第1期B6卷 15-20页

作者： WANG Rongping ZHOU Jinfeng ZENG Lingzhi(department of Applied physics,{2. Polytechnic university,{2. 10002.) beijing Polytechnic Univ Beijing China

A kind of anisotropic scattering in BaTO3:Ce is reported for the perpendicularly and obliquely extraordinary polarized incident beam. The scattering angle is determined by the phase-matching conditions. The experimental results agree well with the theoretical analysis. On the other hand, a new kind of near 90° scattering is presented, a possible mixing mechanism of the light climbing and the photovoltaic effect in BaTiO3:Ce is also pointed out.

关键词： anisotropy scattering light climbing effect photovoltaic effect BaTiO3: Ce crystal

Enantioselective Addition of Diethylzinc to Benzaldehyde by Catalysts of Chiral Heterocyclic Ligands

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Chinese Chemical Letters 1999年第9期10卷 717-718页

作者： Yan HE Yue Lan LI Ye Di GUAN(department of Chemistry, peking university,{2. 100871) peking Univ Dept Chem Beijing 100871 Peoples R China

Several kinds of chiral heterocyclic ligands without hydroxyl group have been synthesized and used as catalysts for the asymmetric addition of diethylzinc to benzaldehyde. These ligands promoted the formation of (S)-1... 详细信息

关键词： chiral heterocyclic ligands hydroxyl group asymmetric catalysis enantioselectivity

On the Construction of Some New Harmonic Maps from R^m to H^m

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Acta Mathematica Sinica,English Series 2001年第2期17卷 301-304页

作者： Yuguang SHI department of Mathematics. peking university,{2. 100871, P. R. China department of Mathematics Peking University Beijing 100871 P. R. China

In this note, we const, ruct some new harmonic maps from R^m to H^m via symmetric methods.

关键词： Harmonic Maps Symmetric Methods

Deprotection of t-Butyldimethylsiloxy (TBDMS) Protecting Group with Catalytic Copper (II) Chloride Dihydrate

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Chinese Chemical Letters 2000年第9期11卷 753-756页

作者： Zhong Ping TAN Lin WANG Jian Bo WANG department of Chemistry, peking university,{2. 100871 peking Univ Dept Chem Beijing 100871 Peoples R China

t-Butyldimethylsilyl (TBDMS) ether can be cleaved upon refluxing in acetone/H2. (95 : 5) in the presence of a catalytic amount of copper (II) chloride dihydrate (5 mmol %).

关键词： TBDMS ether deprotection copper (II) chloride dihydrate

Improvement of Selectivity with Boric Acid in Separating Phenolic Acids by Capillary Zone Electrophoresis

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Chinese Chemical Letters 1998年第1期9卷 87-91页

作者： Hong LONG Ai Jin HUANG Yi Liang SUN(department of Chemistry, peking university,{2. 100871) peking Univ Dept Chem Beijing 100871 Peoples R China

It was shown that in capillary electrophoresis (CE) the addition of boric acid as a complexing agent in phosphate buffer can modulate the separation selectivity of phenolic acids.

关键词： capillary electrophoresis boric acid separation phenolic acid

Simulation of nuclei morphologies for binary alloy

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Science China Mathematics 2010年第11期53卷 2927-2936页

作者： LI DaMing1, & ZHANG PingWen2.1department of Mathematics, Shanghai Jiaotong university, Shanghai 2.02.0, China 2.ey Lab of Mathematics and Applied Mathematics, Center for Applied {2. and Technology and School of Mathematical Sciences, peking university, beijing 100871, China 1. department of Mathematics Shanghai Jiaotong University Shanghai 200240 China2. Key Lab of Mathematics and Applied Mathematics Center for Applied Physics and Technology and School of Mathematical Sciences Peking University Beijing 100871 China

We study the critical nuclei morphologies of a binary alloy by the string method. The dynamic equation of the string, connecting the metastable phase (liquid) and stable phase (solid), is governed by Helmholtz free energy for the binary alloy system at a given temperature. The stationary string through the critical nucleus (saddle point) is obtained if the relaxation time of the string is su?ciently large. The critical nucleus radius and energy barrier to nucleation of a pure alloy with isotropic interface energy in two and three dimensions are calculated, which are consistent with the classical nucleation theory. The critical nuclei morphologies are sensitive to the anisotropy strength of interface energy and interface thickness of alloy in two and three dimensions. The critical nucleus and energy barrier to nucleation become smaller if the anisotropy strength of the interface energy is increased, which means that it is much easier to form a stable nucleus if the anisotropy of the interface energy is considered.

关键词： nucleation crystal morphology string method

Challenges in the theoretical investigations of lipid membrane configurations

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Chinese physics B 2013年第2期22卷 36-44页

作者：涂展春 department of physics Beijing Normal University Kavli Institute for Theoretical physics China Chinese Academy of Sciences

We report some key results in the theoretical investigations of configurations of lipid membranes and present several challenges in this field,which involve（i）the exact solutions to the shape equation of lipid vesicles,（ii）the exact solutions to the governing equations of open lipid membranes,（iii）the neck condition of two-phase vesicles in the budding state,（iv） the nonlocal theory of membrane elasticity,and（v）the relationship between the symmetry and the magnitude of the free energy.

关键词： configuration lipid membrane